Friday mystery object #319 answer

Last week I gave you this unidentified skull from the Dead Zoo to have a go at identifying:

It seems that everyone recognised this as the skull of a gull straightaway – the scars from the salt-glands on the top of the head and the shape of the bill combined to make it a bit of a give-away.

However, working out which species of gull is a bit more tricky, since many are remarkably similar in morphology, making size an important factor for consideration (I’ve talked about this before).

Now size is always a somewhat tricky thing to use for identification, for a variety of reasons. One is that there may be an overlap in size between species, another is that there will often be sexual dimorphism within a species that means you can’t just compare the length against another specimen of a species without considering sex. Then of course there’s age – if it’s not fully grown, it’s going to be smaller. Of course you also have to consider whether the bill sheath is present or absent, as this will add a few millimetres.

On top of all these issues, there’s the problem of how you actually measure the length in the first place. This is something I’ve researched in the past (link to pdf) and it’s a more significant problem than you might think. For example, when looking at the image I originally provided for the mystery object, it looks like the skull measures around 125mm, but if I chop the scale bar from the image, reduce the transparency to 50% and lay it directly over the centreline of the image of the specimen, it turns out to be around 128mm.

Length is apparently 128mm

Add to this the fact that in the original image you can see a shadow under the scale bar, it becomes clear that the scale is somewhat elevated. This is because I raise the scale to be near the vertical midline of the specimen, to help keep everything in focus and limit the effect of parallax error. Normally this is good, because it allows a more accurate estimation of the length of a 3D specimen with a longest axis near the vertical midline, but in this case the longest part of the specimen is actually at the lowest part of the skull, so the elevated scale will make it look slightly shorter than it really is (due to the parallax error I was hoping to avoid…). This means that the specimen is probably closer to 129mm or 130mm in length.

With this in mind, the discussion about the lengths of various gull skulls between Wouter van Gestle (of Skullsite fame), Ric, Tim Dixon, Richard Lawrence, Gerard van den Brink and jennifermacaire needs to be reconsidered.

Richard Lawrence reported skull lengths for a variety of gulls as follows:

6x GBBG: 129 to 141 mm
2x LBBG: 117 mm
6x HG: 111 to 117mm
9x YLG: 111 to 126 mm ( larger with beak sheath though so would be smaller without).

So factoring in a length of 129-130mm for the mystery object it seems to fit well into the range for the Great Black-backed Gull Larus marinus Linnaeus, 1758. So well done to everyone who went for GBBG – this does seem most likely to be a skull from the largest gull species.

Great Black-backed Gull by Andreas Trepte, 2010

Friday mystery object #319

This week I have another unidentified bird skull from the Dead Zoo for you to have a go at identifying:

As usual, you can put your thoughts, questions and suggestions in the comments section below. Have fun!

Friday mystery object #318 answer

Last week I gave you this bird skull from the Dead Zoo in Dublin to have a go at identifying:

It’s a fairly distinctive looking specimen with that massive bill, immediately narrowing down the possible families to two likely contenders – the Toucans (Ramphastidae) or the Hornbills (Bucerotidae).

On closer examination it lacks the serrated bill margins and remarkably long medial (in this case that means ‘towards the midline of the skull’) process of the quadrate bone (a part of the jaw in birds that I’ve blogged about before) that you see in Toucans. So, it’s a Hornbill – as everyone correctly spotted in the comments – but then we have the question of the species.

There are around 60 Hornbill species, with most of them sporting quite distinctive casques which make them quite identifiable (I’ve blogged about several before):

Black Hornbill Ceratogymna atrata

Great Hornbill Buceros bicornis

Bucorvus abyssinicus (Boddaert, 1783) sectioned skull

Northern Ground-hornbill Bucorvus abyssinicus

However, this specimen seems to be lacking a casque. This could be due to a few reasons. There are some casqueless species, such as the Sri Lanka Grey Hornbill, it could be a young female adult from a small casqued species with sexual dimorphism in casque development, or it could be a young juvenile from a species that has a small casque that grows as the animal matures.

Assuming it’s one of these, it’s easy to check the few casqueless species by looking at the overall bill shape, the position of the nares (nostrils) relative to the orbits (eye sockets) and checking the structure of the jugal and quadratojugal (the thin bones on the side of the skull under the orbit) – this last only if you can find a reliable skull image for comparison.

Using Skullsite and images on the internet it’s time-consuming, but straightforward to rule out a lot of possibilities, since most Hornbills have a fairly robust jugal/quadratojugal and nares located much further away from the orbit than you see in the mystery specimen. In fact the only Hornbills with a similar nares/orbit position and gracile (skinny) jugal/quadratojugal and in the right size range (that I was able to find) were in the genus Rhyticeros L. Reichenbach, 1849.

Unfortunately I’ve not found good skull images of juveniles for all of the species to make a final comparison and you can’t just compare the skull of a juvenile with an adult and expect to see the same configuration and development of features, as there’s still growth to happen (something else I’ve talked about before).

So based on the information it looks like jennifermacaire was the closest with her suggestion of Wreathed Hornbill, although I’m leaning slightly more towards the Papuan Hornbill Rhyticeros plicatus (J.R.Forster, 1781).

Hope you enjoyed the challenge!

Friday mystery object #318

Another bird skull for you this week, from the drawer of unidentified specimens:

It’s fairly distinctive, so I doubt you’ll have a problem narrowing down the family, but I’d be interested to hear what species you think this skull belonged to in the comments below.

Have fun!

Friday mystery object #317 answer

Last week I gave you this unidentified bird skull from the Dead Zoo to try your hand at identifying:

mystery317

It seems that everyone recognised it as being from a charadriiform, and one of the waders at that. The first response was from Chris, who made reference to Lewis Carroll’s poem the Walrus and the Carpenter in which the eponymous characters eat an enormous quantity of oysters – hinting that this is an Oystercatcher.

There were some other suggestions that it could be from one of the birds in the genus Tringa, which includes the ‘shanks’ (Redshank, Greenshank, etc.), but the morphology fits one of the Oystercatchers better – in particular that weird constriction about halfway down the mandible when you look at the skull in profile.

This mandibular ‘waist’ is quite unusual and it doesn’t even seem to occur strongly in all of the Oystercatchers, which helps narrow down the likely species within the genus Haematopus, especially when you factor in things like the relative bill proportions, although you have to be careful doing this as there is some sexual dimorphism in the shape of the bill, with the females’ being longer.

The three closest species are the American Oystercatcher, the Sooty Oystercatcher and the Blackish Oystercatcher, but unfortunately I’ve not been able to find good reference skulls all of these species to be able to look for any distinguishing cranial characters. Based on bill morphology I’m leaning towards this being the skull of the American Oystercatcher, Haematopus palliatus Temminck, 1820.

American Oystercatcher by DonaldRMiller, 2010

My next step will be to check through our collections to see if we have comparative material to check the identification (once I get some time – a sadly rare commodity). If I can’t confirm I’ll just stick with Haematopus sp. on the label.

If you’re not familiar with Oystercatchers, they walk along the tideline either prying or breaking open bivalves. In my experience they seem more fond of mussels than oysters, but what do I know?

Another mystery next week!

Friday mystery object #317

For this week’s mystery object I’ve decided to stick with my favourite subject of skulls. This time it’s a bird from the Dead Zoo’s collection, that was in a drawer labelled “Unidentified” – let’s fix that!

Any idea what species this skull belonged to? I have my suspicions, but I’d love to hear what you think.

As always, you can leave your clues, questions and suggestions in the comments section below. Have fun!

Friday mystery object #316

Back to bones this week, with a mystery skull for you to identify. Any idea what species this skull belonged to?

mystery316

I don’t think it will prove too much of a challenge for the bone geeks among you, so please try to be a bit cryptic with your answers to keep it fresh and fun for those who are not so familiar – and that’s a cryptic clue about what it’s not right there 🙂

Have fun!

Friday mystery object #315

It’s been another week of working with the Dead Zoo insect collection for me, so I thought I’d give you one of them to have a go at identifying:

A big bug at around 135mm wingtip to wingtip

I don’t think it’ll be particularly difficult for some of you, so please try to offer cryptic suggestions if you know what is, to keep it challenging for others who aren’t as familiar with these impressive invertebrates.

Have fun!

Friday mystery object #314 answer(ish)

Last week I gave you this guest mystery object, courtesy of Joseph van Sambeek:

Mystery object. Image by Joseph van Sambeek, January 2000

The bony struts reinforcing thin plates of bone show it’s from something that lives in water all the time and which lacks lungs – you can tell this because this structure is what you get when you’re dealing with forces moving in a variety of directions, rather than mainly dealing with the constant force of gravity or compensating for buoyancy that is unavoidable when you live in water, but have lungs.

This means that many of you recognised it as being the neurocranium (that’s the bit of the skull that surrounds the brain) from a fish – more specifically from Sarah Gibson:

The first image is the skull roof, showing the elongated frontals and parietals (front of snout is left in first three images). Second image is a left lateral view, showing the internal parasphenoid that would pass between the two eye sockets. Third image is a ventral view, showing the bottom of the parasphenoid. And obviously last image is posterior view, showing the foramen magnum where the spinal cord would pass through, over the occipital condyle. It just may not look like a skull to some because it’s missing the eye sclera bones, jaws, cheek bones, pretty much anything that is not the skull roof or braincase.

However, as we all know, there are a LOT of different sorts of fish – around 33,600 described species and counting. This can make fish a nightmare to identify. However, there are some great resources out there, like Osteobase which has a very useful identification guide for various elements of a range of fish.

Alas, Osteobase didn’t have anything that fits this mystery specimen, so narrowing down to a species is rather difficult. I had the advantage of knowing that the specimen was collected in Baja California, although that was of little help in trying to get in an approximate area of the fishy family tree based on morphology, and there are still a ridiculous number of fish species is the area.

Sarah Gibson suggested that it may be a Barracuda, and it certainly fits in many aspects, but the shape of the frontals and parietals and details of the point of connection between the parasphenoid (that’s the bottom bar bit you see in the side view) don’t quite fit.

I had almost given up hope, when it occurred to me to concentrate on understanding the unusually large occipital condyle that Allen Hazen noticed, which suggested that it might be a taxon with an extremely extended rostrum (like the paddlefish or swordfish that Jennifer Macaire suggested) but with a weedier body and defined neck region since there would be no need for such a large articulation in a fusiform fish (they’re the muscular type that taper at both ends and have no neck, so don’t move their heads).

With this bizarre sounding fish in mind I was able to fairly rapidly narrow down the possibilities to one of the three species of cornetfish that live in the Pacific. I was delighted to find some great images of the skull of a Red Cornetfish, which matches the morphology very well.

Red Cornetfish Fistularia petimba from the Gulf of Mexico. Image by SEFSC Pascagoula Laboratory; Collection of Brandi Noble, NOAA/NMFS/SEFSC

However, the Red Cornetfish doesn’t really occur in the eastern Pacific, so it’s very unlikely to be that species. The Reef Cornetfish does occur in the eastern Pacific, but has only been reported in Californian coastal waters since November 2015 and this mystery specimen was collected back in January 2000 (which doesn’t make it impossible to be a Reef Cornetfish, just very unlikely). Which leaves us with the most likely identification (although by no means confirmed) of Deepwater Cornetfish Fistularia corneta Gilbert & Starks, 1904.

These long, thin fish can reach up to 2m, but they have tiny mouths that limit them to eating crustaceans, marine worms and smaller fish that they pick up from near the surface of reefs and the sea bed – presumably being harder to spot as a predator thanks to their very small frontal projected area.

I’ve asked Joe to check his specimen against the images of the cornetfish, since there’s nothing better than having a specimen in your hand when attempting an identification.

I hope you enjoyed the challenge!

Friday mystery object #312 answer

Last week I gave you this specimen to identify, which came in as an enquiry after being found in someone’s toilet:

There were a variety of great responses, with some fantastic cryptic clues, including an anagram by Claire Miles (great stuff!). Most opted for this being Stegobium paniceum, which is also known by the aliases Drugstore Beetle, Biscuit Beetle or Bread Beetle.

Stegobium paniceum by Sarefo, 2007

However, the mystery critter has a subtly different pronotum (that’s the plate over the thorax that extends over the head).

Another suggestion was woodworm or one of the false powderpost beetles, which covers a range of wood-boring beetles, with Liberty Hightower correctly giving the more taxonomically constrained suggestion, of something from the Tribe Anobiini (which includes Stegobium). However, my colleague Olivier sent me an email with a very definitive identification, informed by a past experience with this particular pest – the Furniture Beetle Anobium punctatum De Geer, 1774.

These beetles have a distinctive pronotum that supposedly looks like a monk’s cowl, with a more distinctive hump and slightly pinched looking back section than the more smoothly curving pronotum of the Stegobium. They fall into the broad category of woodworm because their larvae feed on wood, making tunnels hidden from view and only becoming visible when they emerge from small holes in the wood as adults, leaving a little pile of wood dust as they go.

The presence of these beetles in a toilet isn’t related to the water in the bowl or even wood of the seat – it turns out that there was a window above the toilet and the adult beetles, in an attempt to leave the building after emerging, were attracted to the light from the window and flew into the glass only to bounce off and land in the toilet.

This attraction towards light in the dispersing adult stage of the beetle is a handy behaviour if you want to keep track of these pests. If you’re concerned you may have active woodworm it’s worth checking your windowsills in the summer to see if you have any of these adult beetles lying around. Of course, there are other species that would also be worth checking for, since there are plenty of beetles whose larvae would be considered woodworm. Keep your eyes peeled!

Friday mystery object #312

A slightly late mystery object this week, so apologies!

Here’s a critter that was sent in for identification that was fished out of someone’s toilet bowl:

Any idea what it is?

As usual you can put suggestions, ideas and any questions in comments box below.

Have fun!

Friday mystery object #311 answer

For the last couple of weeks I’ve been offering up what has been affectionately nicknamed ‘cave snot’ for identification:

mystery311a

The initial goop was a bit too difficult to identify from a photo, so I dug in and pulled out the critter responsible:

mystery311c

This proved much more identifiable, with Chris immediately recognising that it’s the larva of a Caddisfly (not really a fly, but a more moth-like insect in the Order Trichoptera – which means ‘hairy wings’ as palfreyman1414 mentioned). Natalia Maas went one better by alluding to the family – the Philopotamidae or Finger-net Caddis, explaining the goop, which is actually made up of little silk nets shaped like fingers (hence the common name for the family). These nets are used to collect organic detritus and diatoms from flowing water, which the larvae then feed on.

I provided a couple of extra images to help narrow down the identification, since there are only five species in three genera of Finger-net Caddis in Ireland (and England for that matter), which are able to be differentiated from the anterior margin of their frontoclypeus (see the diagram below if you’re not sure what that is).

caddis-frontoclypeus

There’s an excellent website looking at Trichoptera in Ireland, descriptively called TrichopteraIreland, where you can find the details of how to tell the larvae of different genera apart, but the short version is to look at the frontoclypeus and if it has a deep U-shaped notch in it you have a Chimarra marginata, if it has a shallow V-shaped notch in it then you have Philopotamus montanus and if it’s a smooth curve then you have a species in the genus Wormaldia (which could be W. subnigra, W. mediana or W. occipitalis).

Unfortunately you can’t readily tell Wormaldia species apart when they’re larvae, so unless I’m missing a well-hidden notch in the frontoclypeus, we can’t identify this to anything better than genus level – but that’s still a substantial improvement on simply calling it cave snot.

I’ll be taking the specimen to the previous Entomology curator of the Museum, since his area of specialist interest is Caddis, so I’m sure he’ll be able to confirm the identification and I expect there may be some interest in where it came from.

More mysteries next week!

Friday mystery object #311 part 2

Last week I gave you this delightful jar of ‘cave snot’ to have a go at identifying:

mystery311a

Perhaps unsurprisingly, nobody came close to identifying what this is. I didn’t have a clue until I dived in and dissected out a small sample:

mystery311b

Notice the little critter on the left of the image? This immediately made it much more obvious what this stuff was – not something living in its own right but something produced by an animal.

Removing the goop reveals what we’re really dealing with:

mystery311c

mystery311e

mystery311d

I think I’ve given you all the images needed to work out what this is, so rather than just tell you, I’m making this part 2 of the mystery object, with quite a lot more to go on than the first post. So, as usual, you can put your questions, thoughts and suggestions in the comments section below. Have fun!

Friday mystery object #311

This week I have a real mystery object for you, which came in as an enquiry from the bottom of a mine in Ireland that was flooded to the roof with freshwater. It’s earned itself the delightful name of the ‘Clonkeen snot’ thanks to its appearance and texture:

If you click on the image, it will open a large version so you can have a really good look at the fascinating gunk that was fished from the subterranean dankness.

Any ideas what this might be?

As always you can leave your questions, thoughts and suggestions in the comments section below. Have fun!

Friday mystery object #310 answer

Last week I thought it was time for some more bones, so I gave you this specimen from the Dead Zoo to have a go at identifying:

There was no scale, the photo is far from ideal and the specimen isn’t in the best condition, but the animal is pretty distinctive, so I thought it wouldn’t prove too much of a challenge – and it turns out that I was right.

Palfreyman1414 was the first to identify it to genus level, correctly recognising that it was one of the two Notoryctes species of Marsupial Mole from Australia.

The weird limbs are a pretty good indicator this being a digger, with large muscle attachments and robust forelimbs, but it has couple of large claws rather than the ridiculous giant hands of the Old World Moles and it has a shorter skull.

Double prep mole from the Horniman Museum

Double prep of an Old World Mole Talpa europaea from the Horniman Museum & Gardens

The skull is more similar to that of the golden moles of southern Africa, although their rostrum (nosey bits) tends to be more concave while the marsupial moles have a more convex rostrum (and in some cases, weirdly flaring zygomatic arches).

Lateral view of the skull of a Giant Golden Mole Chrysospalax trevelyani from the Grant Museum of Zoology

Now distinguishing between the two species of Marsupial Mole is a bit more tricky, not least because they are quite poorly known animals and there aren’t many specimens available for comparison – this is particularly true of the Northern species, which was first described as recently as 1920.

This is actually quite useful to know, since the mystery specimen came into the collection in 1897 – from Southern Australia – so it’s safe to say it’s the Southern Marsupial Mole Notoryctes typhlops (Stirling, 1889), but that’s not very helpful from a morphological perspective.

So far I’ve not found any useful skeletal features that help differentiate the two species, but apparently their fur colour is a little different, with the Northern species having pinkish or cinnamon fur and the Southern species having yellowish-white to a deep gold. To see what they look like with their fur, here’s the taxidermy partner to the mystery skeleton:

Taxidermy Southern Marsupial Mole Notoryctes typhlops in the National Museum of Ireland – Natural History

As with most moles these subterranean critters have adapted to spending much of their time underground by losing their eyes, investing in some serious digging equipment and tuning in to smells and low frequency sounds.

I hope you enjoyed this little tour around the main moles of the world! More mysteries next week.

Friday mystery object #310

The last few weeks have been rather insect-centric mystery objects, but this week I felt a need for the comfort of something I really know – bones:

mystery310

This skeleton is awesome, although probably a bit too easy for some of you, so cryptic or poetic suggestions are encouraged. Have fun!

Friday mystery object #309

This week I have another specimen for you that I came across while moving the Dead Zoo’s insect collections:

This one’s pretty small – only around 6-8mm. It was collected in Ireland, so if you’re not sure what it is, you only have around 11,999 species to rule out before you get the right answer 😉

Have fun!

Friday mystery object #308 answer

Last week I gave you this beautiful insect to try your hand at identifying:

From the start it was pretty clear it’s a wasp (just look at that characteristic waistline) and palreyman1414 pointed out the key things to look for in making sure it isn’t a fly pretending to be a wasp:

I believe that there are some flies that are camouflaged to look like wasps, but a close look suggests that this thingy has a full complement of four wings, instead of the two plus two halteres (?) that characterises the flies

Now there are a LOT of wasps out there – somewhere in the region of 150,000 species (more than all of the vertebrates put together) so that doesn’t narrow it down much. However, that waist isn’t just pinched-in like your average wasp, it’s petiolate (that’s science-talk for “stalked”), which means it’s one of the Sphecidae.

The large size also helps – most wasps are tiny, so big ones like this are relatively scarce, especially bright metallic green-blue jobs. This distinctive appearance brings to mind for me the Steel-blue Cricket Hunter (see below), but it’s from the wrong part of the world (and it’s more green than blue).

Chlorion aerarium from Maryland, USA, July 2012. Image by USGS Bee Inventory and Monitoring Laboratory

However, we know there are a lot of wasps, so it’s worth looking at close relatives in the Sphecidae, to see if there is anything from the right part of the world (that’s made reasonably easy by using an appropriate reference with a checklist).

It turns out that we don’t need to look too far, as the mystery specimen looks like it’s in the same genus of Cricket Hunters – Chlorion (as suggested by Ilyas) and checking out the species occurring in India has me leaning towards Chlorion lobatum (Fabricius, 1775), which is what abcdefg200 hinted at.

These active hunters don’t eat Crickets themselves, they actually get their energy from nectar, so they’re helpful pollinators. The Crickets face a more grisly fate than just being killed and eaten – they are paralysed, then buried alive with a wasp egg laid on them, which subsequently hatches and the larvae eat the still-living Cricket. Nightmare fodder.

There are a few subspecies of this particular species of wasp, but I’m not even going to try to work out which this might be, since even carrying out a proper identification to species would require time with a microscope and a lot more experience than I have with this diverse, fascinating and above all nightmarish group of insects.

Friday mystery object #308

As I’ve mentioned before, for the last few months I’ve been feverishly moving objects for a gallery lighting project.

That’s pretty much done now (and looking great) so now I’m feverishly moving the Dead Zoo’s collection of over a million insects out to a new home in the National Museum of Ireland’s Collections Resource Centre.

So this week I have an insect for you to identity, which should provide a bit of a colourful change from the usual vertebrate bones:

For some of you this may be way too easy, for others, way too hard. It help to know that this was collected in India and it’s around 25-30mm long.

I hope you have fun identifying it!

Friday mystery object #307 answer

Last week I gave you this specimen from the Irish Room of the Dead Zoo to try your hand at identifying:

mystery307

Now it’s not a particularly difficult species to identify for a keen birder, so I asked for cryptic clues to the identity, and I was not disappointed. Some suggestions were so cryptic I still haven’t managed to work them out!

First in was Jennifer Mccaire who quoted a brief line of poetry:

“…Thou hast no sorrow in thy song, No winter in thy year.”

This is a section of a poem published in 1770 by John Logan – the title being “Ode to the Cuckoo“. Now, it seems likely that Scottish born Logan wrote this about the Common Cuckoo Cuculus canorus Linnaeus, 1758 that breeds in Europe and which looks like this:

Common Cuckoo. Image by Chris Romeiks, 2011

Clearly it’s a different bird (one which mimics the appearance of a female Sparrowhawk) and it’s not quite the same as the mystery object – although there are similarities. However, we must keep in mind that Jennifer is of the North American persuasion, so her thoughts on Cuckoos will probably veer towards the Black-billed Cuckoo or Yellow-billed Cuckoo (or maybe the Mangrove Cuckoo, but that’s not as widespread as the other two).

If you don’t know the difference between these two North American Cuckoos, here’s a handy illustration to help differentiate: